Bear Stearns was saved last March by a merger with JP Morgan , while Lehman Brothers filed for bankruptcy protection last month.

The subpoena seeks internal trading data, personnel information and e-mail and other communications relating to various market rumors that circulated in June and July, the paper reported.

Among these was that Lehman would get access to the Federal Reserve Bank's discount window, that UK bank Barclays would buy Lehman for $15 a share (its market price was near $20), and that major investment firms SAC Capital and Pimco had stopped trading with Lehman, the paper said.

Similar rumors had been circulated involving Bear Stearns, according to a person with direct knowledge of the investigation who declined to be identified because the case is ongoing, it said.

Along with communications related to market rumors, the SEC subpoena seeks all trading positions for Bear and Lehman from June 1 through early July, as well as names of officials responsible for approving trades, details of all client relationships with Lehman and Bear, plus information about any changes in those relationships, USA Today said.